[PATCH] commit: explicitly documented the existence of "last-message.txt"

[Renato Cunha]

Even though the code hg warns an user about the existence of last-message.txt
when a commit fails, I found no trace of it in the documentation. This is an
attempt to make things a bit more explicit.

# HG changeset patch
# User Renato Cunha <renatoc at gmail.com>
# Date 1280158992 10800
# Node ID 505b7d36d5bfdaa505bc0b0016d29c93752c340f
# Parent  c5e555e064d0ceed3a177b656a49f50890d17cfa
commit: explicitly documented the existence of "last-message.txt"

diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -727,7 +727,9 @@
     filenames or -I/-X filters.
 
     If no commit message is specified, the configured editor is
-    started to prompt you for a message.
+    started to prompt you for one, and in case your commit fails,
+    you can find a backup of your message in
+    <repo-root>/.hg/last-message.txt.
 
     See :hg:`help dates` for a list of formats valid for -d/--date.